Separate the geometry update from rebuilding the GraphicsLayer tree

Source/core/rendering/compositing/RenderLayerCompositor.cpp

Index: Source/core/rendering/compositing/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/compositing/RenderLayerCompositor.cpp b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
index 0b4403f6cd5c025d8e163e72e8fc1690f9a2ffcb..a81d4e3c7cfcf7d0df0fad946f9c741401def657 100644
--- a/Source/core/rendering/compositing/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
@@ -520,12 +520,19 @@ void RenderLayerCompositor::updateCompositingLayersInternal()
             needHierarchyAndGeometryUpdate = true;
     }
 
+    if (needGeometryUpdate || needHierarchyAndGeometryUpdate) {
+        // We just need to do a geometry update. This is only used for position:fixed scrolling;
+        // most of the time, geometry is updated via RenderLayer::styleChanged().

[ojan, 2014/03/28 02:26:16]

I know this isn't new to this patch, but this comment is confusing to me.

[abarth-chromium, 2014/03/28 02:37:14]

It's more wrong now.  I'll remove it.

+        TRACE_EVENT0("blink_rendering", "GraphicsLayerUpdater::updateRecursive");

[esprehn, 2014/03/28 02:24:09]

The ones in recalcstyle are all webkit, should we change them to
blink_rendering?

[abarth-chromium, 2014/03/28 02:37:14]

Dunno.  Probably?  "webkit" is so 2012

+        GraphicsLayerUpdater().update(*updateRoot, updateType);
+    }
+
     if (needHierarchyAndGeometryUpdate) {
         // Update the hierarchy of the compositing layers.
         GraphicsLayerVector childList;
         {
             TRACE_EVENT0("blink_rendering", "GraphicsLayerUpdater::rebuildTree");
-            GraphicsLayerUpdater().rebuildTree(*updateRoot, updateType, childList);
+            GraphicsLayerUpdater().rebuildTree(*updateRoot, childList);
         }
 
         // Host the document layer in the RenderView's root layer.
@@ -541,11 +548,6 @@ void RenderLayerCompositor::updateCompositingLayersInternal()
             destroyRootLayer();
         else
             m_rootContentLayer->setChildren(childList);
-    } else if (needGeometryUpdate) {
-        // We just need to do a geometry update. This is only used for position:fixed scrolling;
-        // most of the time, geometry is updated via RenderLayer::styleChanged().
-        TRACE_EVENT0("blink_rendering", "GraphicsLayerUpdater::updateRecursive");
-        GraphicsLayerUpdater().updateRecursive(*updateRoot, updateType);
     }
 
     ASSERT(updateRoot || !m_compositingLayersNeedRebuild);